INTENSITY DISTRIBUTION ACROSS A SOURCE FROM SPECTRAL MEASUREMENTS

The degree of spectral coherence (mu(12)(omega)) over the plane of a double slit is determined from the measurement of spectral changes in Young's interference experiment using the spectral interference law. The experimental and theoretically calculated values of mu(12)(omega) for the experimental parameters agree well within experimental error, thus supporting the theoretical prediction of D. F. V. James and E. Wolf (1991, Phys. Lett. A, 157, 6). The degree of spectral coherence determined is used for estimating the intensity distribution across a source. This new approach, being a simple spectral measurement technique, might find its application in astronomy, particularly for the study of intensity distribution across stars.